rootSystem(D)
i1 : R1=rootSystemB(3)++rootSystemD(4) o1 = RootSystem{...8...} o1 : RootSystem
i2 : D=dynkinDiagram(R1) o2 = DynkinDiagram{{{2}, {}, {}, {}, {}}, {{1}, {3}, {}, {}, {}}, {{}, {}, {2}, {}, {}}, {{5}, {}, {}, {}, {}}, {{4, 6, 7}, {}, {}, {}, {}}, {{5}, {}, {}, {}, {}}, {{5}, {}, {}, {}, {}}} o2 : DynkinDiagram
i3 : R2=rootSystem(D) o3 = RootSystem{...8...} o3 : RootSystem
i4 : R1==R2 o4 = true